Apparatus for industrial cleaning



' May 12,1970 R. B. BLACK.

APPARATUS FOR INDUSTRIAL CLEANING FiledApril e, 1967 4 Sheets-Sheet 1 IN VEN TOR. m2. M

R. B. BLACK APPARATUS FOR INDUSTRIAL CLEANING May 12, 1970 Filed April 6, 196'? 4 Sheets-Sheet 2 M Zf /EUA ATTORNEYS APPARATUS FOR INDUSTRIAL CLEANING Filed April 6, 1967 4 Sheets-Sheet 5 IN VEN TOR.

ATTORNEYS R. B. BLACK 3,511,440

APPARATUS FOR INDUSTRIAL CLEANING 4 Sheets-Sheet 4 May 12, 1970 Filed April 6, 1967 \Hiil 1 m L m w? WEE;

I N VEN TOR. RAW f5. filwh B Y United States Patent" 01 hoe 3,511,440 Patented May 12, 1970 3,511,440 APPARATUS FOR INDUSTRIAL CLEANING Robert B. Black, 2925 Denver St., Corpus Christi, Tex. 78404 Filed Apr. 6, 1967, Ser. No. 632,141

Int. Cl.' B05b 1/24 U.S. Cl. 239-129 9 Claims ABSTRACT OF THE DISCLOSURE Pressurized industrial cleaning system in which fuel is continuously burned under pressure in a combustion chamber having a water jacket and in which the jacket water and preferably also a detergent are introduced into the hot gaseous products of combustion, provision also being made for recovery of detergent not used for clean- GENERAL STATEMENT OF INVENTION AND OBJECTS steam or particles of water, or both steam and water. The

invention is particularly concerned with cleaning equip- -ment, and for that purpose a detergent is preferably also delivered with the steam orsteam and water. For purposesof illustration the invention is hereinafter described with special reference to its use in connection with cleaning equipment. 7

Pressurized cleaning systems of known types commonly include a steam generator comprising extended lengths of tubing in the form of coils located in heat exchange relation to a combustion chamber. By force feeding water into the coils, steam is generated under pressure and then delivered ,to a discharge orpressure nozzle through a flexible hose so that the nozzle may be directed to the desired areas to be cleaned. Equipment of this type is commonly employed in car wash establishments, auto-* motive service stations, radiator and air conditioning repair shops, and other typesof businesses where cleaning equipment is needed. Detergent is usually introduced into the system so that the nozzle delivers both hot detergent solution and steam to the point of use.

Prior art systems of the kind referred to above are subject to numerous disadvantages, including the fact that with the steam coil systems substantial thermal losses occur primarily due to inefficient heat transfer. The products of combustion employed to heat the coils are thus 1 discharged to the atmosphere while still retaining a large amount of heat. Moreover, the prior art coil systems result in discharge to atmosphere of noxious or even toxic gases from the combustion chamber in the environmental area because of incomplete combustion. Still further, the

steam generating coils are very heavy and bulky, frequently comprising as much as several hundred feet of metal tubing, are subject to soot and scale problems (which contribute to further heat losses), and are also y susceptible to rapid deterioration as a result of corrosion and rust.

The prior art systems thus are characterized by inefficient combustion and by inefiicient utilization of the heat of combustion, and with these major deficiencies in mind, v,

the principal objectives of the present invention are the attainment of virtually perfect combustion, combined with close to complete absorption of the heat of combustion for cleaning purposes.

In accordance with the present invention a cleaning system is provided in which fuel is contiunously and efficiently burned at elevated pressures in a combustion chamber after which water is injected into the hot products of combustion prior to delivery thereof to a discharge or pressure nozzle at the point of use. By the system of the present invention, a very large heat economy is effected in consequence of use of the combustion products as a portion of the pressurized hot fluid medium being delivered through the nozzles at the-point of use. Moreover, in accordance with the invention, the combustion is effected'under conditions which prevent the formation of noxious or toxic fumes or gases normally associated with the steam coil cleaning systems. In a typical operation according to the present invention, the gaseous products of combustion, prior to the introduction of water or detergent, comprise about 13.2% carbon dioxide, 0.2% oxygen, and about 86.6% of nitrogen and other inert gases, including water vapor.

In addition to the foregoing, the system of the present invention also makes it practicable to utilize secondary sources of heat associated with the system thereby further increasing capacity and/or efficiency as compared with the prior art steam cleaning systems. For example the invention contemplates utilizing the very substantial heat created by the air compressor, this utilization being accomplished by circulating the water to be introduced into the gas stream, through a cooling jacket associated with the air compressor, thereby preheating the water prior to its introduction into the gas stream. Moreover, the invention also contemplates utilizing a considerable amount of the heat developed in the combustion chamber to further preheat the Water, before it is introduced into the gas stream, this being accomplished by circulating the water through a jacket surrounding the combustion chamber. In this way some of the heat of combustion is carried into the system by the water, and at the same time the heat transfer to the water in the jacket surrounding the combustion chamber serves to 'limit the internal wall temperature of the combustion chamber to a point where heat deterioration does not occur.

By employing a pressurized combustion chamber with water injection instead of the bulky steam coils of prior art systems, the invention makes possible the provision of a very compact system which is also free from other disadvantages of steam coil systems. For instances, by atomizing the preheated water directly into the intensely hot products of combustion under pressure, the necessary surface area for heat transfer is accomplished to produce steam, not water, or a mixture of the two without need for the heavy, bulky steam coil. Moreover, the steam generating components of the invention are not subject to soot and scale problems nor the rapid deterioration which are characteristic of steam coil systems.

Further, the equipment employed in the system of th present invention is much less bulky and lighter in weight in relation to its capacity than is the equipment of the steam coil type. I

In accordance with another aspect of the invention and in contrast to the prior art steam coil arrangements, the system of the present invention makes possible the control or adjustment of the operating conditions so as to generate a hot gaseous cleaning medium containing the intensely hot products of combustion as a carrier, and also containing either steam or finely subdivided Water, or a mixture of steam and water'carried in the stream of the gaseous cleaning medium. The operating conditions may be adjusted so that the steam may be either superheated or saturated. In'addition detergent may or may not be'added, as desired, and when used the detergent may be introduced as an aqueous solution either independently of the waterintroduced, or in solution in the water, in a manner which will be explained more fully hereinafter. The control and adjustment capabilities of the system thus make possible compliance with a wide variety of operational requirements. For most normal uses, the amount of water or detergent solution should predominate over the steam.

Use of the pressurized combustion product gases as a carrier for the cleaning constituents substantially increases the velocity of the cleaning constituents as they escapefrom the nozzles, thus further enhancing the cleaning or'scrubbing efliciency of the system.

Still another object of the invention is to substantially decrease the time required to produce steam or hot water from a cold start over prior art systems.

Still another object of the invention is to provide a system in which the detergent may be recovered when the discharge nozzles are not in use, this being accomplished by separation of the detergent from the combustion gases and recirculation of the detergent into the system, thereby substantially reducing detergent and heat losses which are commonly associated with prior art systerns.

The invention further contemplates a combustion chamber for the purposes above referred to of special materials and design providing maintenance of high internal Wall temperatures for efiicient combustion but limited to a point well below that where heat deterioration of the equipment might result, with external wall temperatures which are not conducive to fires or explosions or hazard ous to personnel working in the area where the system is installed.

A further object of the invention is to utilize a type and design of refractory system in the combustion chamber which will result in the lowest possible thermal inertia when the system is started and shut down.

BRIEF DESCRIPTION OF FIGURES How the foregoing and other objects and advantages are obtained will appear more fully from the following description referring to the accompanying drawings, in which:

FIG. 1 is a schematic view of a preferred embodiment of the system according to the present invention;

FIG. 2 is a side elevational view of the apparatus showing various of the components which are diagrammed in the schematic of FIG. 1;

FIG. 3 is a view showing the combustion chamber in longitudinal section and showing various of the connections and controls included in the system;

FIG. 4 is a transverse sectional view taken as indicated by the line 44 on FIG. 3, but to an enlarged scale;

FIG. 5 is an enlarged transverse sectional view taken as indicated by the line 5-5 on FIG. 3; and

FIG. 6 is a view similar to FIG. 1 but illustrating a modified system.

DETAILED DESCRIPTION OF FIGURES Referring first to FIG. 1, the major components of the system include the combusion chamber C, the air compressor P, the motor M, nozzles N, N the fuel supply tank F, detergent supply tank D, and the detergent recovery system R. Before considering the interconnection of these various components, attention is first directed to the fact that in the schematic view of FIG. 1 the combustion chamber C is illustrated purely diagrammatically. The construction of this combustion chamber should first be considered and for that purpose reference is made to the iztructural illustration of the combustion chamber in The combustion chamber is of double walled construction, the outer and inner walls 7 and 8 being spaced from each other to provide a jacket through which a cooling medium may be circulated. Inside of the double walled chamber is an inner liner 9 which is spaced from the inner jacket wall 8 and which is preferably made of a refractory type of metal, for instance one of the stainless steels such as Austenitic stainless steel. A typical refractory type steel of this kind is known as #314 Austenitic stainless steel and has a composition, as follows:

Percent Carbon .25 Manganese 2.00 Silicon 3.00 Phosphorous .040 Sulphur .030 Chromium 26.00 Nickel 22.00 Iron Remainder In a typical combustion chamber according to the invention, the stainless steel refractory liner 9 is approximately in thickness and each of the inner and outer jacket walls 7 and 8 are approximately in thickness, the dead air space between the inner jacket wall 8 and the refractory liner 9 being of the order of A in thickness.

At its inlet end the combustion chamber is provided with a fitting 10 having a venturi throat. Air is introduced into the combustion chamber through this fitting from the air inlet connection 11. Fuel is also introduced into this fitting, preferably at the constriction of the venturi, as by a nozzle 12. Toward the end of the combustion chamber adjacent to the fuel and air inlets there is a transverse wall 13 defining a small chamber 14 into which the air and fuel are introduced. A series of curved nozzle tubes 15 (three being here shown) have their inlet ends communicating with the chamber 14 and their discharge ends positioned within the combustion chamber itself so that the fuel and air entering the combustion chamber are caused to swirl or proceed in a vortex as the fuel and air advance through the combustion chamber. These nozzle tubes 15 appear to good advantage in FIG. 5 which also shows the arrangement of the combustion chamber walls 7, 8 and 9. The initial introduction of the fuel and air into the chamber 14 and the subsequent passage of the mixture through the nozzle tubes 15 and into the combustion chamber with a swirling motion all assist in ensuring intimate intermixture of the fuel and air, with consequent uniformly complete combustion of the fuel.

Toward the opposite end of the combustion chamber, a second venturi throat type fitting 16 is provided, serving as the initial discharge from the combustion chamber. Preheated water is introduced into the stream of hot combustion products flowing through the discharge throat 16 by means of a nozzle '17 which is positioned at the constriction of the discharge venturi.

The preheated water for introduction through the nozzle 17 is derived from the connection 18 communicating with the jacket space surrounding the combustion chamber. The jacket space also has a pair of inlets indicated at 19 (see FIG. 5) for delivering the preheated Water from the jackets surrounding the two cylinders of the compressor shown.

Returning now to the diagram of FIG. 1, the fuel is supplied from the tank F through the fuel supply line 20 having a solenoid operated shut off valve 21 controlled by the switch 22. In addition the fuel supply line is provided with a controllable needle valve 23. These parts 21, 22 and 23 appear also on FIGURE 3 from which it will be seen that the shut off switch 22 and the needle valve control 23 are mounted upon a control panel 24 which also serves to mount several controls mentioned herebelow. The air for combustion is delivered from the compressor P through the connection 24, which communicates with the connection part 11 shown in FIG. 3. An air pressure gauge line 25 extends from the fitting 11 to the pressure gauge 26 which is mounted on the control panel 24.

The compressor itself may be of any known construction, for instance a V-4 cylinder compressor. The cylinders of the compressor, such as indicated at 27 are provided with an air inlet 28 (see FIGS. 2 and 3), and the compressor is driven by the electric motor M which serves also to drive the water pump 29.

As shown in FIGS. 1 and 2, the water pump receives its supply through the line 30 which is connected with the reservoir 31 associated with the detergent recovery system to be described later. The water supply line 32 delivers water into the reservoir 31 under the influence of the ball float valve 33.

From the pump 29 the water is delivered through the line 34 provided with an adjustable (preferably gate) valve 35 (see FIGS. 1 and 3), which is located on the control panel 24. The water line 34 returns from the control panel and delivers the water to the cooling jacket 36 associated with the cylinders of the compressor B. After flowing through the compressor jacket the water is delivered through the connections 19 above referred to into the cooling jacket surrounding the combustion chamber. As above mentioned in connection with FIGURE 3, the water leaves the jacket for the combustion chamber through the fitting 18 and is introduced into the stream of combustion products by the nozzle 17. The flow from the fitting 18 to the nozzle 17 is controlled by the solenoid operated valve 37 which is controlled by the switch 38, the switch being located on the control panel 24 as appears in FIG. 3.

As seen in FIG. 3, the discharge 16 is connected with a fitting 39 which in turn is connected with a fitting 40, through the interposed perforated plate 41 (see also FIG. 4). Several additional fittings and connections are associated with the fitting 40, the physical interrelation of which is not of importance but the flow pattern of which is of significance and is shown in FIG. 1. Thus, a connection 42 delivers the stream of combustion products and steam or water particles to a T-fitting 43, the central connection of which is provided with a varied discharge outlet, this valve being indicated at 44 and serving to discharge the combustion products and stream to the atmosphere when the valve is opened. During normal operation the valve 44 is closed, as will be explained more fully herebelow.

As shown in FIGS. 1, 2 and 3 a temperature gauge 45 is provided on the control panel and, as shown in these figures, this gauge is provided with a temperature responsive capsule 45a located in the chamber 40 and having a connection 45b extended therefrom to the gauge on the control panel, thereby providing a temperature reading of the gaseous mixture in the discharge. As shown in FIG. 1, the T-fitting 43 is connected by another line which is valved as indicated at 46 with another T 47 one side of which is connected by a line 48 with a third T 49, the latter serving to divide the gaseous stream between the two lines 50 and 51 which are extended to the discharge or pressure nozzles N, N.

The pressure nozzlesare of known construction and need not be considered in detail herein, but it is noted that each one of them is provided with a discharge orifice, for instance of /s" or A" diameter and also with a manual valve 52 which closes when released. The T- fitting 47 is also connected by a line 53 with the detergent recovery system shortly to be described.

The line 53 is provided with a valve 53a of automatic pressure release type, so that upon the build up of pressure in the system above the pre-set release pressure value, the valve 53a will open and thereby open the detergent recovery line 53.

As seen in FIGS. 1 and 2, detergent is fed into the system from the detergent supply tank D through a connection 54 having a manual shut off valve 54a and a controllable needle valve 55 which, as shown in FIG. 3, is mounted upon the control panel 24. The detergent sup ply line 54 introduces the detergent into the systemclose 6 to the connection of the nozzle supply lines 50 and 51, for instance between the T-fittings 47 and 49.

Attention is now called to the provision of an air pressure line 56 (see FIGS. 1, 2 and 3) which extends from the air supply fitting 11 (see FIG. 3) and which has branches 57 and 58 (see FIGS. 1 and 2) communicating respectively with the fuel and detergent supply tanks F and D. These connections make possible the use of the compressor for pressurizing the fuel and detergent in the supply tanks. In a typical operation this is accomplished by operating the compressor with the fuel valve 21 closed and with the valves 44 and 46 associated with the discharge from the combustion chamber also closed, so that air under pressure developed in the compressor P will be delivered to the tanks F and D, thereby pressurizing the fuel and detergent supplies therein.

The equipment may also include provision for pressurizing the fuel and detergent tanks from another source of air under pressure, for instance from the source indicated at 59 which is connected with the line 56. With this system it is preferred to employ a pair of check valves 60 and 61 in the line 56 and to arrange the connection 59 so that air introduced therefrom will enter the line 56 between the check valves 60 and 61. The independent air supply line 59 desirably also has a shut oif valve 62. In this way the fuel and detergent supply tanks may alternatively be pressurized either by the compressor P or by an independent source of air or other gas under pressure, such as is commonly available in many shops, service stations and the like. If desired, one or the other of these pressurizing systems may be omitted from the equipment.

The motor M is adapted to be controlled by a switch 63, this switch also serving to control the ignition system indicated diagrammatically at 64 which supplies the desired current for the ignition device 65. The type of ignition system employed will depend upon the type of fuel being used. In the event of use of a gaseous or volatile fuel such as gasoline, a spark plug will ordinarily be used as the device indicated at 65, and in this case device 64 will be designed to supply the required high voltage current for spark plug operation. On the other hand in the event of employment of diesel oil as fuel, a glow plug may be employed at 65, and in this case the device 64 will be designed to provide the desired low voltage but high amperage current adapted to effect continuous heating of the ignition element of the glow plug. The switch 63 is advantageously of the type provided with an On button and an 011? button, such as indicated at 63a and 63b on the control panel 24 which is shown in FIG. 3.

The upper part of the detergent recovery unit R comprises a cyclone type separator 66 having an upwardly directed gas discharge 67. Liquid constituents drop back into the reservoir 31 and thus return to the system by way of the water supply line 30.

OPERATION To consider a typical starting operation and also the continued normal operation of the system, it is here first asumed that the fuel and detergent tanks F and D have been pressurized, in either of the manners described above. With valve 46 closed and with valve 44 open, the fuel valve 21 is opened and in view of this the operation of the compressor P by the motor M delivers air under pressure along with the fuel into the combustion chamber C, wherein it is ignited by the spark or glow plug 65. During this initial starting of combustion, it is preferred also that the solenoid actuated water supply valve 37 be opened so that water will be circulated through the cooling jacket surrounding the combustion chamber. The products of combustion are delivered through the discharge 16 to the connection 42 from which the gas is passed through the T-fitting 43 and to the atmosphere through the open valve 44. The condition of the combustion may then be visually observed and the amount of fuel introduced adjusted by means of the valve 23, this adjustment preferably being set so as to minimize and preferably prevent the formation of carbon in the discharged gases. Too rich a mixture will yield discharge gases which not only will be darkened by carbon but which also will contain some carbon monoxide. Too lean a fuel air mixture results in lowering the performance, so that free oxygen remains, with the possibility of oxidizing the refractory metal of the inner liner 9 of the combustion chamber. Adjustment to a condition yielding substantially clear products of combustion represents the preferred condition in which the fuel is substantially completely burned and in which no measurable or substantial quantity of carbon monoxide is present.

When the desired combustion conditions are attained and remain stable, the valve 46 is opened and the valve 44 closed, whereupon the manual valves 52, 52 at the nozzles may be opened for delivery of the gaseous cleaning medium to the desired point of use.

Detergents may be introduced into the system by opening valve 55 and adjusting that valve to provide the quantity of detergent needed for any particular cleaning operation.

It will be noted that when valve 44 is closed and valve 46 open, at any time when one or more of the nozzle valves 52 are opened, the products of combustion, steam and detergent will flow to and through the discharge nozzle or nozzles. On the other hand when the nozzle valves 52, 52 are both closed, the pressure relief valve 53a will open as a result of the increase of pressure in the system and then gases, steam and detergent will all flow through the pipe 53 to the detergent recovery system, detergent and water particles being separated from the gases and descending to the reservoir 31, while the gases are discharged at 67. This system not only provides for recovery of detergent which would otherwise be lost, but also recovers some heat which would otherwise be lost, by virtue of the detergent and water returning to the reservoir 31.

OPERATIONAL CHARACTERISTICS, VARIABLES AND ADVANTAGES Certain additional aspects of the operation of the system are now pointed out with particular reference to FIG. 3:

First, with reference to the combustion chamber itself, as noted above a thin refractory linner shell is provided, as indicated at 9. While certain ceramic types of refractories may be employed for this shell, it is preferred to employ a thin refractory type of Austenitic stainless steel, as already noted. The spacing of this shell from the inner Wall 8 of the water jacket surrounding the combustion chamber provides, in effect, a dead air space which not only shields the inner wall 8 of the water jacket from direct heat transfer from the burning fuel but which also, as the result of radiation from the refractory liner to water jacket, avoids an excessively high temperature differential at the inner and outer faces of the refractory shell 9.

The primary advantage of the thin metallic type refractory sleeve, with a surrounding dead air space, is the resultant very low thermal inertia combined with the fact that it permits high but not excessive refractory temperatures. Moreover, unlike ceramic refractory, such a metal refractory sleeve is not subject to breakage.

The low thermal inertia provided by the use of the thin stainless steel refractory liner 9 is of advantage from several aspects of the operation of the system. In the first place this facilitates rapid warm up. Indeed, in a typical system having parameters such as referred to above as well as herebelow, production of steam may be attained within as short a time as 3 seconds after ignition. On the other hand the low thermal inertia is also of advantage at the time of shut off. Upon terminating the supply of fuel, the temperatures will drop below steam producing temperatures in a matter of seconds.

The wall construction of the combustion chamber as above described gives service over long periods of time and makes practical high temperature combustion without subjecting the outer walls of the chamber to excessive temperatures. In a typical operation the refractory wall temperature approximates 1700" F. However, wall temperatures from about 1500 F. to 2000 F. may be used.

The inlet tubes or nozzles 15 at the input end of the combustion chamber not only provide a swirling motion of the fuel and air mixture entering the combustion chamber, but these tubes further serve to prevent flash back of the combustion into the mixing or turbulence chamber 14. This effect is achieved by maintaining the total cross sectional flow area of the tubes 15 relatively small, so that relatively high linear velocities of fuel and air input are maintained during operation.

In a typical installation, the temperature of the combustion products at the discharge end of the combustion chamber approximates 3100 F. The water is introduced through the nozzle 17 into the throat of the venturi fitting 16, where the water is instantly broken up into a micromist of millions of small particles which pass at high velocity into the chamber in the fitting 39. Intimate inter-1 mixture of the hot combustion products and the water particles and effective heat transfer from the combustion products to the water particles is here effected and is enhanced by the presence of the perforated plate 41, in consequence of which some flash steam generation occurs. After passage through the ports or apertures in the plate 41, the mixed products, steam and water particles pass into the chamber 40, from which the gas-water-steam mixture is delivered to the connections ultimately leading to the discharge nozzles.

It will be noted that the plate 41 has a ring of perforations surrounding an imperforate central area, so that the plate, in effect, provides a target surface against which the advancing stream of fine water particles impinge. The total cross sectional area of the ports or apertures in this plate should be sufiicient to avoid any excessive resistance to flow. Preferably this plate should not build up back pressure of more than about 5 p.s.i., in a system operating at a normal combustion pressure of the order of p.s.i.

With regard to the injection or introduction of the water, it is first noted that water is preferably introduced through a nozzle adapted to effect spraying or atomization of the water. The quantity of Water may be varied widely, with resultant variation in the amount and condition of the water or moisture present in the system. First, it is of course possible to use the system with relatively little water, but ordinarily, the quantity of water introduced would not be less than that quantity which could be completely converted to steam, by flash steam generation, as the incoming water meets the high temperature stream of combustion products. Increase in the amount of water beyond that quantity will result in the presence of some water as such in fine particle form and, for most cleaning purposes, it is preferred that the quantity of water introduced be more than quantity which would result in conversion of all of the water to steam, so that both water and steam will be present. Indeed for many purposes it is preferred that the water content predominate over the amount of steam present, and this can readily be accomplished by increasing the quantity of hot water introduced.

Certain other variables will also influence the conversion of the water introduced into steam, for instance the temperature and the pressure established for normal combustion.

It is contemplated that the Water pump 29 be provided with a bypass set at the desired pressure, for instance a value of the order of 1 /2 times the pressure maintained in the system, so that the water introduction will occur readily under this pressure differential. The water control valve 35 may be adjusted to any desired value, the water not actually being used being recirculated through the bypass around the pump in known manner.

In connection with the compressor P, it is first pointed this will be an important factor in determining the pressure of operation of the system. Assuming that the operating pressure is aboutv 100 p.s.i. in a typical installation, this increase in pressure of the air from atmospheric pressure raises the temperature of the air from normal atmospheric temperature (65 or 70 R), up to about 275 F.

'This preheating of the air is of course advantageous in the attainment of the desired combustion temperature.

Any of a variety of fuels may be employed in the system, such as gasoline, kerosene, diesel oil, natural gas, propane fuels and other hydrocarbon fuels.

' With respect to the water system, with a water supply temperature of about 70 F. and with equipment of the proportions and capacities described more fully here- 'below, the passage of the 'water through the cooling jacket 36 of the compressor will raise the temperature of the "water approximately 40 F. Upon passage of this water through the jacket surrounding the combustion chamber, 'the temperature will rise an amount on the order of about 160 F., so that the water will then be at about 27 F. at the point of inlet through the nozzle 17. Con- 'sidera ble economies are effected in this way, by the successive stages of preheating of the water in the jacket of the compressor ber. With regard to the introduction of detergent, it is first pointed out that although the detergent may be introduced "along with the water, it is preferred to introduce the water 'and detergent separately, for instance in the manner indicated in the diagram of FIG. 1. Here it will be noted that 'the'water is introduced into the venturi discharge fitting "16 closely adjacent to the discharge end of the combustion' chamber and that the detergent is introduced into and in the jacket of the combustion chamthe connection 48 at a point closely adjacent to the lines (50 and 51) which connect the nozzles N with the system. The introduction of the water at a point close to the combustion chamber is desirable because this reduces the temperature of the combustion products which, therefore, flow through the remainder of the system at'the reduced temperature. The introduction of the detergent at a point close to the nozzles is of advantage because the operator, when adjusting the detergent valve 55, will more quickly observe the result of an adjustment, than would be the case were the detergent introduced earlier in the system.

'The detergent is preferably employed in the form of a liquid concentrate or concentrated solution. Detergents suitable for use in this system are materials such as trisodium phosphate base to which is added liquid soaps or detergents, preferably of the long chain organic type with low sudsing characteristics. The operator may determine how much, if any, detergent is introduced into the system merely by adjustment of the needle valve 55 on the control panel. As already indicated, in the event of closure of all of the manual valves 52, 52 on the nozzles N, N, any detergent which is being introduced into the system will be recovered in the detergent recovery unit R and this detergent will return to the system through the water suply. p The equipment may be arranged in any of a variety of ways, for instance the various units of the apparatus appropriately interconnected in accordance with the conditions encountered at any particular installation site. Alternatively, at least certain of the components may be mounted upon a base or frame, such as indicated at B in FIG. 2 and, if desired, this base may be equipped with wheels or rollers 68. In FIG. 2 it will be seen that the may be installed in a fixed or permanent location and V combustion chamber C, compressor P, motor M and recovery unit R are all mounted on the wheeled base, and in the event that movement of the base independently of the fuel and supply tanks is contemplated, the interconnecting pipe lines 54, 56 and 20 would of course be made flexible. In the installation generally illustrated in FIG. 2, it will be seen that the control panel 24 is mounted upon structural members 69 which extend upwardly from the base and which serve also to support a shield plate 70 disposed in front of the combustion chamber C in the region below the control panel 24.

Equipment in a typical installation will include a combustion chamber of about 18 inches in length and 6 inches in diameter. The compressor may be of the multiple cylinder type driven for example by a 5 horsepower electric motor and capable of delivering about 20 cubic feet per minute of air compressed to p.s.i., which is a typical pressure which may be established and maintained with a nozzle orifice in the discharge gun N of about A inch diameter.

A water pump suitable for use with the equipment here being described is one of the positive displacement type capable of delivering up to 200 gallons of water per hour at 100' p.s.i.

With the foregoing equipment, and when operating at 100 p.s.i., the fuel consumption (using gasoline) is about 1.5 gallons per hour.

When operating as described just above and also with the air and water temperatures referred to earlier in this specification, the discharge temperature of the gaseous stream of combustion products and water or steam approximates 290 F.

The working pressure may readily be altered by changing the size of the orifice in the discharge nozzle, a change from an orifice of about inch, to an orifice of about inch will result in an increase in the operating pressure of from about 100 p.s.i. to about p.s.i. This will also increase the temperature of the discharging gases, which would be of the order of 300 F. at 150 p.s.i.

MODIFICATIONS In considering modifications, attention is first directed to the arrangement shown in FIG. 6. In this figure, it is first noted that where the same or essentially similar parts appear, they have been given the same reference numerals or letters as in FIGS. 1 to 5.

There are two chief differences in the system of FIG. 6 as compared with the system of FIG. 1, as follows:

First, instead of employing an electric motor M for driving the compressor and the water pump, aninternal combustion engine (gasoline or diesel) indicated diagrammatically at E is employed. This engine is provided with an ignition system including a transformer 71 and a distributor 72, this ignition system also being controlled by the switch 63. If desired an engine starter (not shown) may be integrated into this system, but since that feature forms no part of the present invention it is neither illustrated nor described.

The water system is somewhat differently arranged in the embodiment of FIG. 6 as compared with FIG. 1, partly in view of the employment of the internal combustion engine instead of the electric motor. Thus in FIG. 6 the water supply line 73 is connected with the pump 29 and delivers water through the adjustable valve 35 to the cooling jacket 36 of the compressor P. From this jacket the water is delivered by way of the pipe 74 to the cooling jacket 75 of the engine E. Thus the water will pick up more heat in cooling the engine and is then delivered through the line 76 to the water jacket surrounding the combustion chamber in which the water picks up a third stage of heat prior to its admission into the discharge 16, under the control of the shut ofi valve 37.

As in the arrangement of FIG. 1, the arrangement of FIG. 6 includes fittings and valves 43, 44, 46, 47, 49 and 53a, all of which are similarly arranged, except for the 11 fact that'the valve 53a which is the automatic pressure release-valve is not shown as delivering the gas stream to a detergent recovery system. Although such a system could be added to the embodiment shown in FIG. 6, the valve 53a is here shown as providing for discharge of the gas stream directly to atmosphere.

In the embodiment of FIG. 6 a separate source of air underpressure such as indicated at 59 in FIG. 1 is not employed, but it is contemplated that thedetergent and fuel tanks be pressurized by initially closing valves 44 and 46 and operating the compressor P in the absence of fuel and water, as by closing valves 21 and 37. In this way the tanks D and F maybe pressurized as in the embodiment of FIG. 1.

In still further modifications, it is possible, according to certain circumstances, to omit some parts of the equipment or systems already described. For example, a modified cleaning system according to the invention can be provided without the motor or engine driven compressor, in industries or plants where compressed air at adequate pressure and volume is already available. In such an installation the combustion chamber identical to that shown would be preferably wall mounted with the discharge end at the bottom. The fuel and detergent tanks would be pressurized by the air system as shown and described, and in the event water is not available at suitable pressures, a small fractional horse power motor driven water pump employed to supply water at the desired pressures and volumes. Ordinarily the pressure requirements would be up to 150 psi. and the volume requirements up to 200 gallons per hour. The water would of course be preheated by passage through the jacket of the combustion chamber, as in the embodiment already described.

In this type of installation the preferred fuel is gasoline, although cheaper fuels, such as diesel oils or kerosene, may be used after the system is first heated to insure proper ignition. This system is extremely compact and simple and virtually free from any moving parts subject to wear.

I claim:

1. Steam supply equipment including, in combination with a discharge nozzle, a combustion chamber having inlet means for fuel and airand an outlet for discharging a stream of gaseous products of combustion, an air compressor delivering compressed air to the combustion chamber and having a heat transfer cooling jacket, and means for delivering cooling water through said jacket and then into the stream of combustion products for flash steam generation and for delivery of the steam with the combustion products to the discharge nozzle.

2. Equipment according to claim 1 in which the combustion chamber is provided with a heat transfer cooling jacket and in which means are provided for delivering the cooling Water from the compressor jacket through the combustion chamber jacket in advance of the point of delivery into the stream of combustion products.

3. Equipment according to claim 2 and further including an engine for driving the compressor having an engine cooling jacket, and means for delivering the cooling water through the engine cooling jacket before it is delivered to the cooling jacket of the combustion chamber.

4. Steam supply equipment including, in combination with a discharge nozzle having a shut-off valve, a combustion chamber, means for introducing air and fuel under pressure into the combustion chamber, an offtake leading from the combustion chamber and serving to deliver a stream of combustion products from the combustion chamber to the nozzle, a water supply system for introducing water into the offtake for flash steam generation and for delivery of the steam with the combustion products to the nozzle, means for introducing detergent into the offtake for delivery with the combustion products and the steam to the nozzle, and a detergent recovery system connected with the ofrtake and including means for recovering detergent when the shut-off valve for the discharge nozzle is closed.

5. Equipment according to claim 4 in which the detergent recovery system further includes means for introducing the recovered detergent into the water supply system.

6. Equipment according to claim 4 in which the detergent recovery system includes a cyclone separator for separating detergent from the combustion products, and a water reservoir into which the separated detergent is delivered, said water reservoir being connected with the water supply system and serving as a Water supply for the water supply system.

7. Steam supply equipment including, in combina tion with a discharge nozzle, a combustion chamber of double wall construction providing a water jacket, a refractory inner liner for the combustion chamber spaced inwardly from the inner wall of the water jacket, an offtake from the combustion chamber for delivery of a stream of combustion products to the nozzle, and means for circulating water through the water jacket and then delivering the water into the otftake for flash steam generation and for delivery of the steam with the combustion products to the nozzle.

8. Steam supply equipment including, in combination with a discharge nozzle, a combustion chamber having concurrently open inlet and outlet means respectively providing for fuel and air inlet and for discharge of a stream of gaseous products of combustion, a compressor for introducing air for combustion under pressure through the inlet means and for establishing pressure in the outlet stream of gaseous products, the combustion chamber being provided with a heat transfer cooling jacket, and means for delivering cooling water under pressure higher than that of the stream of combustion products through said jacket and then into the stream of combustion products for flash steam generation and for delivery of the steam with combustion products to the discharge nozzle.

9. Steam supply equipment including, in combination with a discharge nozzle having a shut-off valve, a combustion chamber having concurrently open inlet and outlet means respectively providing for fuel and air inlet and for discharge of a stream of gaseous products of combustion, a compressor for introducing air for combustion under pressure through the inlet means and for establishing .pressure in the outlet stream of gaseous products, means for delivering cooling water under pressure higher than that of the stream of combustion products into the stream of combustion products for flash steam generation and for delivery of the steam with combustion products to the discharge nozzle, and a pressure responsive blow-off valve connected with said offtake between the combustion chamber and the nozzle and providing for discharge of the stream of combustion products when the shut-off valve of the nozzle is closed.

References Cited UNITED STATES PATENTS 1,825,131 9/1931 Shepherd 239129 2,476,171 7/1949 Williams 239l29 2,860,918 11/1958 White et a1. 239-129 3,092,325 6/1963 Brown et al. 239129 3,341,081 9/1967 King 239129 EVERETT W. KIRBY, Primary Examiner W105 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO' S11 440 Dated 12 1970 Inventor(s) R B Black It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

LL01. 2, Line 49, "not" should read --hot--- (fol 5, Line 39, "vuricd should rcml valved-- L701. 5, Line 11, "stream" should read steam-- Col. 7, Line -14, lim1cr should read -inm r-- Col 8 Line 57 after "than" insert --tl:ut--

SIGNED QEAlED Anew Edward M. Fletcher, 15 NIH-IA! I. SGHUYIM, JR. Attesfing Officer Gomissionar of Patents 

